It's an electronic bubble level, I fail to see the "wonderfulness".
I have a big bubble level on the hitch. It tells me how much off I am from side to side, so I level the side-to-side. The Travel Mate Pro does the same thing.
I have to unhook the hitch so when I do that I level front to back using the bubble level on the side near the leg switches. The Travel Mate Pro does the same thing, but costs $100 more, plus I have to have my phone in my hand.
I honestly fail to see any advantages to another gadget that costs a whole heck of a lot more than what my two bubble levels cost. If you love gadgets...